Many Nissan and Infiniti vehicles are equipped with a variable voltage control system.

In the Electronic Service Manual (ESM), section CHG-Charging System, vehicles with variable voltage control systems, which use the IPDM E/R to provided the PWM signal to the alternator, as described in this article will have a section titled POWER GENERATION VOLTAGE VARIABLE CONTROL SYSTEM and a System Diagram similar to the one above.

A Variable Voltage Control system is different in that it monitors all power usage via the battery current sensor/ This allows the ECM to control the alternator in two major ways:

System Components and Operation

1. IC voltage regulator (built into the alternator)

2. Battery current sensor

3. Electronic Control Module (ECM)

4. Intelligent Power Distribution Module in Engine Room (IPDM E/R)

Accessory Installation

If an electrical accessory is grounded directly to the negative battery post:


CONSULT-III plus can monitor the variable voltage control system output and perfrom active tests on most vehicles that are equipped with varible voltage control. Refer to the Electronic Service Manual (ESM) for specific vehicles to determine which CONSULT-III plus functions are available.